2,272 research outputs found
KK-DUALITY FOR SELF-SIMILAR GROUPOID ACTIONS ON GRAPHS
No full textWe extend Nekrashevych’s KK-duality for C∗-algebras of regular, recurrent, contracting self-similar group actions to regular, contracting self-similar groupoid actions on a graph, removing the recurrence condition entirely and generalising from a finite alphabet to a finite graph. More precisely, given a regular and contracting self-similar groupoid (G, E) acting faithfully on a finite directed graph E, we associate two C∗-algebras, O(G, E) and Ô(G, E), to it and prove that they are strongly Morita equivalent to the stable and unstable Ruelle C*-algebras of a Smale space arising from a Wieler solenoid of the self-similar limit space. That these algebras are Spanier-Whitehead dual in KK-theory follows from the general result for Ruelle algebras of irreducible Smale spaces proved by Kaminker, Putnam, and the last author
K-theory for group C*-algebras
No full textThese notes are based on a lecture course given by the first author in the Sedano Winter School on K-theory held in Sedano, Spain, on January 22-27th of 2007. They aim at introducing K-theory of C*-algebras, equivariant K-homology and KK-theory in the context of the Baum-Connes conjectur
[[alternative]]Shape and KK Masses
No full text[[abstract]]我們討論在六維時空模型中，額外維度空間的形狀對現象學的影響。兩個以週期性條件緊緻化的維度可以夾角Θ，此角對Kaluza-Klein態的質量有很大影響。我們特別考慮Θ<<1的情況，大部分的KK態質量會比Θ=90°時大很多，但是有一群KK態的質量會相較下小很多，我們討論這些Light KK態的KK數n1、n2滿足哪些條件，並以一個具體Θ為例找出最輕的一些KK態，這些態通常具有蠻大的KK數。如果在Universal Extra Dimension模型中來討論，KK數守恆會造成許多Light KK態無法衰變，而形成穩定粒子，這些粒子可能成為黑物質。
Brito et al SRCT-PSICHE MHNM-KK-OT-36 (11.45 µm voxel size)
No full textTwo fragments of the holotype of the loricariid catfish Afroloricaria saharaensis gen. et sp. nov. (MHNM-KK-OT 36a & 36c from the early Late Cretaceous of Jbel oum Tkout (Morocco) were studied in three dimensions using synchrotron X-ray mycrotomography. Measurements were performed at the PSICHÉ beamline of SOLEIL Synchrotron (Saint-Aubin, France) using a pink beam (63–69 keV), a single propagation distance of 36 cm, and 3900 projections. The available field of view was extended horizontally by positioning the rotation axis off-centre, and extended vertically by using a helicoid acquisition with a continuous vertical movement of the sample during multiple rotations of the sample. The volume (5.727 μm voxel size) was reconstructed from the combined radiographs using PyHST2 software, with a Paganin phase retrieval algorithm.
We here provide a slightly reduced version (crop, rescale 8-bit, binning 2x2x2) of the reconstructed tomograms (i.e. virtual slices) we used for the segmentation and 3D renderings presented in the paper. After binning the voxel size becomes 11.45 µm. </p
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Collins asymmetries in inclusive charged KK and Kπ pairs produced in e[superscript +]e[superscript -] annihilation
No full textWe present measurements of Collins asymmetries in the inclusive process e[superscript +]e[superscxript -] → h[subscript 1]h[subscript 2]X, h[subscript 1]h[subscript 2] = KK, Kπ, ππ, at the center-of-mass energy of 10.6 GeV, using a data sample of 468 fb[superscript -1] collected by the BABAR experiment at the PEP-II B factory at SLAC National Accelerator Center. Considering hadrons in opposite thrust hemispheres of hadronic events, we observe clear azimuthal asymmetries in the ratio of unlike sign to like sign, and unlike sign to all charged h[subscript 1]h[subscript 2] pairs, which increase with hadron energies. The Kπ asymmetries are similar to those measured for the ππ pairs, whereas those measured for high-energy KK pairs are, in general, larger.United States. Dept. of EnergyNational Science Foundation (U.S.)Alfred P. Sloan Foundation (Fellowship
Systematic control of the electrical conductivity of poly (3,4-ethylenedioxythiophene) via oxidative chemical vapor deposition (oCVD)
No full textSystematic variation in the electrical conductivity of poly (3,4 ethylenedioxythiophene) (PEDOT) was achieved by oxidative chemical vapor deposition (oCVD). For oCVD, both the oxidant, Fe(III)Cl-3, and 3,4 ethylenedioxythiophene (EDOT) monomer are introduced in the vapor phase. A heated crucible allows for sublimation of the oxidant directly into the reactor chamber. Spontaneous reaction of the oxidant with the monomer results in the rapid (> 200 nm thick film in 30 min) formation of pi-conjugated PEDOT thin films directly onto a temperature controlled substrate. As the substrate temperature is increased from 15 degrees C to 100 degrees C, increasing conjugation length and doping level of the PEDOT chains are observed by Raman spectroscopy. The X-ray photoelectron spectroscopy (XPS) study showed that the surface consists of PEDOT polymer chains doped with Cl- ions in the absence of metallic impurities such as Fe. This contrasts to the surface composition of commonly used PEDOT:PSS films, where the PSS segregates to the surface. Scanning transmission electron microscopy (STEM) with energy dispersive X-ray analysis (EDX) study clearly demonstrates that the bulk composition is uniformly maintained throughout thickness of the film and is identical to the surface concentration. Both the substrate and air side interfaces were abrupt. The doping level could also be controlled by changing substrate temperature and accordingly, the work function was tuned from 5.1 to 5.4 eV, a range desirable for optimizing hole transport by lowering the charge injection barrier. The controllability of doping level and work function of oCVD PEDOT offers great potential advantages for optimization of the performance of organic devices. (C) 2007 Elsevier B.V. All rights reserved.This research was supported by, or supported in part by, the
U.S. Army through the Institute for Soldier Nanotechnologies,
under Contract DAAD-19-02-D-0002 with the U.S. Army
Research Office. The authors thank LG Chemicals Ltd. for the
measurement of work function. The content does not necessarily
reflect the position of the Government, and no official
endorsement should be inferred
Fucoxanthin promotes translocation and induction of glucose transporter 4 in skeletal muscles of diabetic/obese KK-Ay mice
No full textFucoxanthin (Fx) isolated from Undaria pinnatifida suppresses the development of hyperglycemia and hyperinsulinemia of diabetic/obese KK-Ay mice after two weeks of feeding 0.2% Fx-containing diet. In the soleus muscle of KK-Ay mice that were fed Fx, glucose transporter 4 (GLUT4) translocation to plasma membranes from cytosol was promoted. On the other hand, Fx increased GLUT4 expression levels in the extensor digitorum longus (EDL) muscle, although GLUT4 translocation tended to increase. The expression levels of insulin receptor (IR) mRNA and phosphorylation of Akt, which are in upstream of the insulin signaling pathway regulating GLUT4 translocation, were also enhanced in the soleus and EDL muscles of the mice fed Fx. Furthermore, Fx induced peroxisome proliferator activated receptor γ coactivator-1α (PGC-1α), which has been reported to increase GLUT4 expression, in both soleus and EDL muscles. These results suggest that in diabetic/obese KK-Ay mice, Fx improves hyperglycemia by activating the insulin signaling pathway, including GLUT4 translocation, and inducing GLUT4 expression in the soleus and EDL muscles, respectively, of diabetic/obese KK-Ay mice
The dietary effect of milk sphingomyelin on the lipid metabolism of obese/diabetic KK-A(y) mice and wild-type C57BL/6J mice
No full textPurified milk sphingomyelin (SM) was obtained from lipid concentrated butter serum (LC-BS) by successive separations involving solvent fractionation, selective saponification, and silicic acid column chromatography. The SM obtained was given to obese/diabetic KK-A(y) mice and wild-type C57BL/6J mice. SM supplementation significantly increased fecal lipids paralleled with a decrease in non-HDL cholesterol levels in the serum and neutral lipids and in cholesterol levels in the livers of KK-A(y) mice. The reduction of liver lipid levels also resulted in a decrease in the total fatty acid content of the KK-A(y) mice livers, while n-3 fatty acids derived from the conversion of a-linolenic acid (18:3n-3) increased due to SM supplementation. In contrast to the KK-A(y) mice, little change in the serum and liver lipids was observed in wild-type C57BL/6J mice. The present study suggests that SM may be effective only in subjects with metabolic disorders
Cen A and its interaction with the X-ray emitting interstellar medium
No full textAs the closest radio galaxy, Centaurus A is a powerful laboratory for the X-ray study of radio-emitting structures and their interactions with the hot interstellar medium (ISM). This paper details our interpretation of the remarkable X-ray enhancement which caps the inner southwest radio lobe, at a radius of about 6 kpc from the galaxy center. The shell of X-ray-emitting gas is hotter than the ambient ISM, and overpressured by a factor of 100. We argue that it is heated compressed material behind the supersonically-advancing bow shock of the radio lobe, the first example of the phenomenon to be clearly detected. The results demonstrate that Cen A is actively re-heating nearby X-ray-emitting gas. The shell's kinetic energy is ~ 5 times its thermal energy, and exceeds the thermal energy of the ISM within 15 kpc of the center of the galaxy. As the shell dissipates it will have a major effect on Cen A's ISM, providing distributed heating.As the closest radio galaxy, Centaurus A is a powerful laboratory for the X-ray study of radio-emitting structures and their interactions with the hot interstellar medium (ISM). This paper details our interpretation of the remarkable X-ray enhancement which caps the inner southwest radio lobe, at a radius of about 6 kpc from the galaxy center. The shell of X-ray-emitting gas is hotter than the ambient ISM, and overpressured by a factor of 100. We argue that it is heated compressed material behind the supersonically-advancing bow shock of the radio lobe, the first example of the phenomenon to be clearly detected. The results demonstrate that Cen A is actively re-heating nearby X-ray-emitting gas. The shell's kinetic energy is ~ 5 times its thermal energy, and exceeds the thermal energy of the ISM within 15 kpc of the center of the galaxy. As the shell dissipates it will have a major effect on Cen A's ISM, providing distributed heating
KK-duality for self-similar groupoid actions on graphs
No full textWe extend Nekrashevych’s KK-duality for C∗-algebras of regular, recurrent, contracting self-similar group actions to regular, contracting self-similar groupoid actions on a graph, removing the recurrence condition entirely and generalising from a finite alphabet to a finite graph.
More precisely, given a regular and contracting self-similar groupoid (G, E) acting faithfully on a finite directed graph E, we associate two C∗-algebras, O(G, E) and̂ O(G, E), to it and prove that they are strongly Morita equivalent to the stable and unstable Ruelle C*-algebras of a Smale space arising from a Wieler solenoid of the self-similar limit space. That these algebras are Spanier-Whitehead dual in KK-theory follows from the general result for Ruelle algebras of irreducible Smale spaces proved by Kaminker, Putnam, and the last author
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